class ResourceController

class ResourceController {
  
  /**
   * Creates an oEmbed resource response.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The request.
   *
   * @return \Symfony\Component\HttpFoundation\Response
   *   The oEmbed resource response.
   */
  public function get(Request $request) {
    $asset_url = $request->query
      ->get('url');
    $resource = \Drupal::keyValue('media_test_oembed')->get($asset_url);
    if ($resource === 404) {
      $response = new Response('Not Found', 404);
    }
    else {
      $content = file_get_contents($resource);
      $response = new Response($content);
      $response->headers
        ->set('Content-Type', 'application/' . pathinfo($resource, PATHINFO_EXTENSION));
    }
    return $response;
  }
  
  /**
   * Returns an example thumbnail file without an extension.
   *
   * @return \Symfony\Component\HttpFoundation\BinaryFileResponse
   *   The response.
   */
  public function getThumbnailWithNoExtension() {
    $response = new BinaryFileResponse('core/misc/druplicon.png');
    $response->headers
      ->set('Content-Type', 'image/png');
    return $response;
  }
  
  /**
   * Maps an asset URL to a local fixture representing its oEmbed resource.
   *
   * @param string $asset_url
   *   The asset URL.
   * @param string $resource_path
   *   The path of the oEmbed resource representing the asset.
   */
  public static function setResourceUrl($asset_url, $resource_path) {
    \Drupal::keyValue('media_test_oembed')->set($asset_url, $resource_path);
  }
  
  /**
   * Maps an asset URL to a 404 response.
   *
   * @param string $asset_url
   *   The asset URL.
   */
  public static function setResource404($asset_url) {
    \Drupal::keyValue('media_test_oembed')->set($asset_url, 404);
  }

}